Random oriented decoder for label decoding

ABSTRACT

A decoder for reading labels and decoding them which does not require that the decoder be oriented relative to the label for operation to obtain data for the automatic tabulation of the item as to price, weight and item designation. The position of the label under the decoder is not critical and the decoder obtains an image from the label and decodes it and automatically centers the image in certain embodiments. The decoder scans the indicia on the circular label in a rotary fashion when the indicia is arrayed in radial wedges. The indicia is comprised of &#39;&#39;&#39;&#39;bits,&#39;&#39;&#39;&#39; each data &#39;&#39;&#39;&#39;bit&#39;&#39;&#39;&#39; comprising a pair of contrasting areas, the ratio of said areas in each &#39;&#39;&#39;&#39;bit&#39;&#39;&#39;&#39; defining the binary status of each &#39;&#39;&#39;&#39;bit.&#39;&#39;&#39;&#39; The scanned information from the label is entered in a cash register or computer for inventory purposes or at a checkout counter.

United States Patent Mohan et al.

[451 Feb. 15, 1972 [54] RANDOM ORIENTED DECODER FOR LABEL DECODING [72] lnventoni WH- L. Mail; Samuel P. Wu, both of Barrington, 111.

[52] Us. Cl. ..235/6l.ll E, 250/219 D, 235/61.12 N [51] [H.Cl ..G06k7/l4,G06k 19/06,G01n 21/30 [58] l'lellldseal'dl ..235/61.12,61.11,61.115,61.9;

[ Cited UNITED STATES PATENTS 2,919,851 1/1960 Otis .......235/61.9 2,952,181 9/1960 Maurer ..88/14 2,974,254 3/1961 Fitzrmurice... ..315/10 3,059,521 10/1962 Clemens ..88/1 3,061,730 10/1962 .Iankowitz ....250/203 3,229,100 1/1966 Grianias ....250/202 3,239,674 3/ 1966 Aroyan ..250/203 3,409,760 11/1968 Hamiach ..235/61.12 3,413,447 11/1968 La Men ..235/61.6 3,414,731 12/1968 Sperry ..250/2l9 3,418,456 12/ 1968 Hamiach ..235/61.1 1

Primary Examiner-Maynard R. Wilbur Assistant Examiner-Robert M. Kilgore Attorney-Jacque L. Meiater [57] ABSTRACT A decoder for reading labels and decoding them which does not require that the decoder be oriented relative to the label for operation to obtain data for the automatic tabulation 01' the item as to price, weight and item designation. The position of the label under the decoder is not critical and the decoder obtain an image from the label and decodes it and automatically centers the image in certain embodiments. The decoder scans the indicia on the circular label in a rotary fashion when the indicia is arrayed in radial wedges. The indicia is-comprised of bits, each data bit comprising a pair of contrasting areas, the ratio of said areas in each bit" defining the binary status of each bit." The scanned information from the label is entered in a cash register or computer for inventory purposes or at a checkout counter.

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SHEET U7UF 17 nn nn n INVENTORS MAL/14M Z. MOf/AA/ SAMUEL P Mums PAIENTEDFEB 15 m2 SHEET OBUF 17 INWJ/WORS l V/LA/AM L Mam 3444064 W/murs ATTORNEYS PATENTEDFEBI 5 I972 I SHEET OSUF I? III II IL I IIIIL I N VEN TOR5 SHEET 12 0F 17 SAMUEL ML L/TS @{WATTORNE YS P ATE NTQIJFEB 151912 PATENTEDFEB 15 ma SHEET 130F 17.

W/LL/AM L Max-MN INVENTORS mwuaz r. Mums PAIENTEBEEB 15 m2 SHEET 150F 1T NNN INVENTORS MAL/4M Z Ma /AM 544/064 P MAL/7'5 Z ATTORNEYS RANDOM ORIENTED DECODIIR FOR LABEL DECODING 1. Field of the Invention This invention relates, in general, to means for encoding and decoding labels such as used on produce or any other items to allow detection and recording of the items as they pass a checking station to provide continuous inventory and/or checkoutcontrol.

2. Description of the Prior Art Inventory controls have long presented a problem and the checking out and recording of produce or other items has generally been done manually. For example, in a grocery store the clerk looks at the price on each item and records it on the cash register and moves the item into the group which have been previously recorded. Such controls are tedious, time consuming and subject to error and semiautomatic systems have been developed wherein each item to be checked out carried a coded ticket which could be torn from the item and inserted into the data handling system for the recording and accumulation of the price, inventory and other data. Such systems remove the human error which could occur in the previous manual systems wherein the checkout clerk might misread the price or might punch the wrong knobs on the cash register, for example.

However, tear-off tickets are subject to being accidentally removed and lost and require that each item be handled to remove the ticket and insert it into the data system.

Certain other automated systems such as readers require that the data be aligned and oriented before it can be entered into the data handling system.

SUMMARY OF THE INVENTION The present invention relates to means of encoding and decoding labels such as would be used on produce, staples and any items sold in general merchandise stores, for example, for the purpose of supplying both the purchaser and the merchandiser with pertinent data relative to the item upon which it is placed. Although the invention is of particular applicability to stores, it is to be realized, of course, that the invention is also applicable to inventory control as, for example, in a factory wherein the receiving and disbursing of parts is maintained.

In particular, a coded label may be attached to articles of any shape which may in turn be intermingled so that the system is not limited to having items of the same size and the label may be decoded by a suitable hand probe decoder to provide data for the automatic tabulation of the item as to price, weight, item designation or any other required data needed in modern computer control business transactions.

Upon decoding the label the sensor probe and its associated electronics is capable of supplying data to an electronically operated cash register to show the purchaser and the operator the indication of the item cost and thus eliminate the human element in a mechanical tabulation of purchased items as now occurs in general merchandising.

The essence of the invention is that the coded labels used with the hand probe decoder is of such a design that specific orientation or positioning of the label relative to the probe is not required for the proper decoding of the label as is th general case with related devices.

The hand probe sensor may be an intensity measuring device utilizing the more usual quantities of optics relating to intensity and need not satisfy an equation of motion or .boundary conditions as do devices utilizing diffraction techniques and requiring coherent illumination or self-luminous targets.

It is an object of this invention to provide means for encoding and decoding labels wherein the label may have a random orientation and displacement of its axis relative to the sensor probe.

Another object is to provide a device that does not require symmetrical placement of the label relative to the sensor.

Another object is to provide means for generating digital signals sequentially and/or parallel representative of data stored on a coded label.

' Yet another object of the invention is to provide data to an electronic .cash register and/or computer such that substantially all results previously obtained by manual actuation of the cash registers may be accomplished without error and very rapidly without requiring the cashier or clerk to read and manually punch information into the cash register.

Another object of the invention is to provide a coded label that can be permanently affixed to the item being purchased and can be read from any position by a scanner as it passes by a checkout point.

Other and further objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed disclosure thereof and the drawings attached hereto and made a part hereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the random oriented decoder of this invention installed at a checkout counter of a supermarket;

FIG. 2 is a partially cut away view of the hand probe of this invention;

FIG. 3 is an exploded view of a scanning system of the invention;

FIG. 4 is an exploded view of a modification of the scanning system of the invention;

FIG. 5 is an exploded view of another modification of the scanning system of the invention;

FIG. 6 is aplan view of a label of the invention;

FIG. 7 is a plan view of another type label;

FIG. 8 is a plan view illustrating the relationship between the label and the hand probe;

FIG. 9 is a schematic view of a system for detecting and decoding information;

FIGS. 10A through 10L illustrate wave shapes portions of the system;

FIGS. "A through illustrate various wave forms ob-' tained in the system of the invention;

FIG. 12 is a partially cut away view of a modified sensor of the invention;

FIG. 13 is an exploded view of a modified scanning system of the invention;

FIG. 14 is a schematic view of a system according to the invention;

FIG. 15 is a plan view of a label according to the invention illustrating various relationships;

FIGS. 16A through 16L illustrates wave forms in the invention;

FIG. 17 illustrates a label usable with the invention;

FIG. I8 illustrates another label usable with the invention;

FIG. 19 is a schematic view of a system according to the invention;

FIGS. 20A-20G illustrate wave forms in a system of the invention;

FIG. 21 is an exploded view of a modification of the invention;

FIGS. 22A and B illustrate a label and sensor orientation;

FIGS. 23A through D illustrate wave shapes appearing in a system of the invention;

FIG. 24 is a plan viewof a label of the invention;

FIG. 25 is a partially cut away view of the hand probe of the invention;

FIG. 26 is an exploded view of a modification of the invention;

FIG. 27 is a schematic view of a system according to the invention;

FIG. 28 is a plan view of a label according to the invention;

FIG. 29 is a plan view of another label;

FIG. 30 is a block view of a system according to the invention;

FIGS. 31A through I illustrate various wave forms in the invention;

FIG. 32 illustrates a modification of the apparatus of the invention;

FIG. 33 illustrates a label of the invention; and

in various FIG. 34 illustrates a modification of FIG. 21.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. -1 is a perspective view of a pair of checkout counters 16 and 16, each of which have hand probes 11 and 11' connected to electrical cables 12 and 12 that are supported by supports 13 and 13 and which connect the hand probes to registers and computers 14 and 14 respectively. Customer monitoring stations 17 and 17' are mounted on the counters 16 and 16' so that the customer may monitor the information.

The package 19 is then positioned on the counter 16' under the probe 11 and has a label (not seen) which is being read by the probe 11'.

FIG. 2 is cut away view of a first form of the probe 11 and comprises a housing 22 which has an extension 23 with an operate button 24 and includes a sensor array (not shown) and a rotating optical wedge 26 which is driven by a motor mounted in the extension 23. A lens 27 focuses the image through the wedge 26 on the sensing array and is mounted above the label 21. The lower portion 28 of the probe 11 is transparent so that the operator can see the label and approximately align the probe over the label. The portion 28 might be of glass or a suitable plastic, for example.

FIGS. 6 and 7 illustrate respectively, different forms of coded labels, the one illustrated in FIG. 6 designated by 21 and having a plurality of pie segments 22, 23 and 24. The label 26 illustrated in FIG. 7 has a plurality of pie-shaped segments 27, 28 and 29. FIG. 8 illustrates the relationship between the label 21 and the end 31 of the probe 11.

The present invention allows lateral and angular misalignment of the probe 11 and the label 21 and still correctly detects information on the label. In FIG. 8, MI is the radius of the sensor probe see-through housing. RD is the radius of the coded label. RS is the radius of rotation of the sensor image and D is the displacement of the center of the scan from the center of the coded label.

The displacement requirements are that D must be less than RHminus RD where RH is greater than RD plus D and 2RS is greater than RD with the center of scan and the center of the sensor probe housing being coaxial.

The phase modulated label 21 illustrated in FIG. 6 comprises n number of binary bits plus an end of cycle bit designated as n+1. The end of cycle bit is 22 in FIG. 6. Each other binary bit comprises a light and dark contrast area with a total angular width being 4:. The beginning of each bit segment is a light area and if the bit is a true (I), the light area will have an angular width (0,) where 0,=30 If the bit is false the light area (0.) will have an angular width of 30,=0 It can be seen that with the randomly placed label 21 being scanned by a circular scanning sensor whose image is shown as (P) in FIG. 8 that the data generated by the scanning sensor will be frequency modulated, phase modulated train of pulses. The time interval per bit (Tb), assuming a constant sensor image velocity (Vp), will be a function of the effective radius of the scan (R relative to the center of the coded label. Where and u L) p fi) where 4: is the angle per bit in radians and the angle [3 is much less than 30. If the radius of scan approaches the diameter of the coded label then the time per bit is o i.) B) The ratio of maximum time per bit to minimum time per bit is The limitation of the angular requirement per bit is a function of how large a coded label is desired and the resolution of the scanning sensor. For the example shown in FIG. 8, a one inch diameter label containing fifteen bits is shown as a drawing enlarged six times. The see-through probe has a diameter l percent larger than the coded label's diameter and the diameter of the circular scan is percent less than the diameter of the coded label.

There are many ways for nutating an image to produce a circular scan and FIG. 3 illustrates one such method. It is to be realized that the housing of the sensor and the mechanical supporting portions have been removed for purposes of clarity. A lens 36 is mounted in a rotatable housing 37 which is supported in the probe 11. The lens 36 is mounted so that it is offset from the center axis of the housing 37. The housing 37 is driven by a motor 38 which has output shaft 39 that carries a driving gear 41 that engages teeth formed in the edge of the housing 37. A sensor array 42 receives an image through the lens 36 from the label 21 as shown by the dotted line on the label 21. The electrical data thus generated in the sensor array 42 by scanning the light and dark contrast areas of the label are amplified in an operational amplifier 43 and supplied to output terminal 44. FIG. 4 illustrates another way of effecting a circular scan. The output gear 41 of motor 38 drives a rotatable housing 46 mounted in the probe 11 which supports an optical wedge 47 which changes the direction of the impinging light rays to cause the image of the sensor 42 to traverse a circular path as shown by dotted line on the label 21. The field lens 48 collimates the image of the sensor 42 adequately to allow for a change in depth of the front focal position of the coated label when it is not placed upon a flat surface. The electrical output data from the sensor array 42 is supplied to output terminal 44 through operational amplifier 43. A further lens 49 may also be included in the system if desired.

FIG. 5 illustrates another method of producing a circular scan wherein the motor 38 through the gear 41 rotatably drives an opaque disk 51 which has a small opening 52. The distance of the opening 52 from the optical axis 53 and the magnification factor of the objective lens 54 will determine the radius of scan. The disk 51 is caused to rotate by the motor 38 and allows the output from the label 21 to pass through the disk aperture only along its effective path as shown by the dotted line to the sensor array 42. The collecting lens 56 focuses upon the sensor array 42.

The operation of the decoder relative to the scanners illustrated in FIGS. 3, 4 and 5 is shown schematically in FIG. 9 with relevant wave forms illustrated in FIG. 10. The label of FIG. 6 is used in this embodiment.

The sensor array is chosen so that an effective radial length to tangential width is greater than three to one for purposes of good signal-to-noise ratio (optical-electrical) and the electrical signal corresponding to the optical contrast gradient from bit to bit will be as shown in FIG. 10B as a sensor scans the label. FIG. 10A shows the wave form B in linear form. The start of the code series is at T and the end is at bit n-H. The electrical data is fed from the operational amplifier 43 to an amplifier 60 which includes an amplifier 61 and a logic gate 62. The logic gate 62 determines that the data used is above a certain minimumas defined by a reference voltage applied to terminal 63. The output of the amplifier 60 is supplied to a differentiator 64 which produces an output wave form shown in FIG. 10C. The positive going spikes are used to trigger the true" one-shot multivibrator 66 of stage 67. The negative going spikes are used to trigger the false" one-shot multivibrator 68 of unit 67. These gates are shown in FIGS. 10D and 10E, respectively, and are used for multiple purposes. The time duration of the one-shot" gate is very short compared to the minimum interval generated by a given bit and is on the order of 5 percent or less. The leading edge of wave form 10D is used to generate the start of the true gate in the true-false computer gate logic 69. While the leading edge of wave form 10E is used to generate the end of the true" gate of element 69.

The true gate is wave form 10F while its compliment is the false gate shown as 100. Assuming that the data brightness is valid for the given portion of the cycle that is defined by 10F and 10B then the gates 10F and 10G will be used to operate bit analogue computer 71.

As stated, the present type of scanning produces a frequency modulated, phase modulated signal train. So as not to have 

1. Means for detecting and decoding a single channel of information consisting of a start code and a plurality of data bits, each bit comprising a pair of alternating contrast areas, the relative angular extent of each contrast area of the pair defining the binary status of the data bit, said single channel of information being arranged in annular form on a medium, comprising sensor means, imaging means interposed between said medium and said sensor means for sequentially imaging said coded information on said sensor means thereby to generate a frequency modulated phase modulated output signal wavetrain from said sensor means including a start signal, each cycle of said wavetrain being representative of a data bit, the polarity of the data bit being defined by the relative angular extent of the contrast areas within said data bit, amplifier means connected to said sensor means and responsive to said output signals therefrom to amplify the bit information contained therein. computer means connected and responsive to the output of said amplifier means to determine the binary status of said bit information, gating means connected to said computer means for gating out said bit information, and recycle bit generator means responsive to the output of said computer means to generate a recycle signal upon receipt of said start signal.
 2. Means for detecting and decoding a single channel of information in accord with claim 1 wherein said sensor means has a radial length to tangential width ratio of at least three to one.
 3. Means for detecting and decoding a single channel of information arranged in annular form and having a discrete start code disposed on a medium, comprising rotatable sensor means, imaging means interposed between said medium and said sensor means for sequentially imaging said coded information on said sensor means thereby to generate frequency modulated, phase modulated output signals from said sensor means representative of said coded information, decoding means for converting said output signals serially on a bit by bit basis after receipt of the signal representing said start code, said decoding means being operative without any signal other than said output signals, said decoding means comprising amplifier means connected to said sensor means and responsive to said output signals therefrom to amplify the bit information contained therein, true-false gate logic means responsive to the amplified output signals to generate true or false gate outputs, analog computer means connected and responsive to the true or false gate outputs of said true-false gate logic means to determine the binary status of the said bit information, gating means connected to said analog computer means for gating out said bit information, and recycle bit generator means responsive to the output of said analog computer means to generate a recycle signal upon receipt of said start signal.
 4. Means for detecting and decoding concentrically coded labels consisting of a fixed number of alternate light and dark annular bands phase modulated with respect to each other, comprising sensor means for generating output signals representative of said annular bands, imaging means for imaging said sensor on said label, scanning means for effecting a linear raster scan of said sensor means with respect to said label, thereby to generate said output signals, decoding means connected to said sensor means and responsive to said output signals therefrom to generate decoded informatiOn whenever said output signals are equal to the fixed number of said annular bands and comprise two sets of coded data one of which is the mirror image of the other.
 5. A system for detecting information on a circularly coded label comprising a label having a single data channel consisting of pairs of alternating contrast areas defining data bits and arranged in annular form, one of said data bits comprising a ''''start'''' bit, the relative angular extent of each contrast area of the pair defining the binary status of the data bit, sensor means for generating output signals representative of said coded bits, imaging means interposed between said label and said sensor means for imaging said sensor means upon said single data channel, scanning means for rotating said sensor image to thereby sequentially scan said single data channel, and decoding means for serially converting said output signals on a bit-by-bit-basis after receipt of the signal representing said start bit.
 6. An identification system comprising a label comprising a single data channel arranged in annular form consisting of pairs of alternating contrast areas each pair of alternating contrast areas defining a data bit cycle and one of said data bit cycles comprising a start bit, the relative angular extent of each contrast area of the pair defining the binary status of the data bit cycle, sensor means, imaging means interposed between said medium and said sensor means for sequentially imaging said coded information on said sensor means thereby to generate a frequency modulated phase modulated output signal wavetrain from said sensor means including a start signal, each cycle of said wavetrain being representative of a data bit, the polarity of the data bit being defined by the relative angular extent of the contrast areas within said data bit, amplifier means connected to said sensor means and responsive to said output signals therefrom to amplify the bit information contained therein, computer means connected and responsive to the output of said amplifier means to determine the binary status of said bit information, gating means connected to said computer means for gating out said bit information, and recycle bit generator means responsive to the output of said computer means to generate a recycle signal upon receipt of said start signal.
 7. An identification system comprising a label comprising a fixed number of pairs of alternate contrasting annular bands, each of said pairs of bands comprising a bit cycle, the relative radial width of each band of the pair defining the binary status of the bit cycle, the said bands being concentrically disposed about a center, sensor means for generating output signals representative of said annular bands, imaging means for imaging said sensor means on said label, scanning means for effecting a linear scan of said sensor means with respect to said labels thereby to generate said output signals, and decoding means connected to said sensor means and responsive to said output signals therefrom to generate decoded information whenever said output signals are equal to the fixed number of annular bands and comprise two sets of coded data one of which is the mirror image of the other. 